

def is_isbn_or_key(word):
  isbn_or_key = 'key'
  if len(word) == 13 and word.isdigit():
    isbn_or_key = 'isbn'
  if '-' in word and len(word.replace('-', '')) == 10 and word.replace('-', '').isdigit():
    isbn_or_key = 'isbn'
  return isbn_or_key


